Had a call in the middle of the night from this number which I didn't recognise. I answered sleeepily and the person hung up. The next day I had a missed call again from this number. I had a friend who had gone on holiday in Morocco and realising this was an African number wondered if  she was in trouble so called the number and got a buzzing noise at the other end. The whole scenario bothered me so I called my mobile fone provider who advised it was a Nigerian number - don' know anyone there and isn't this where most scams are run from  so was staring to get worried. The mobile provider can't verify if anything untoward has gone on re the account as they have to wait 24 hours to verify... I am really concerned about this.